FYI, and thanx Rob for solving the confusion.
-------- Original Message --------
Subject: Questions about APEL
Date: Mon, 25 Apr 2005 16:03:15 +0100
From: Byrom, R (Rob) <[log in to unmask]>
To: Antonis Zissimos <[log in to unmask]>
Hi,
If possible, please forward this reply to the LCG-Rollout list (I don't
have direct privileges to post mail to this group).
Thanks,
Rob Byrom
> >I am not certain I am understanding correctly. Are you asking for a
> >backup of these log files so they can be recovered if lost or an
> >archive so that every transaction a gatekeeper records is kept and
> >accessible in some fashion, i.e. on disk and/or restored from backup?
> >If we don't need to archive, what is the the required lifetime of the
> >log files?
> >
> >Rotated backups of these areas are easy. Keeping an archive for the
> >life of the LHC may not be, so please help me understand better.
>
> I see no answer in this post, so can someone explain why it is
> necessary
> to backup the log files? According to the APEL user guide the GOC and
> the site R-GMA MON box keeps all the necessary information in their
> databases.
I believe it's not necessary to backup any log files indefinitely. As
you mention, the Apel will store a copy of log file data within its own
database and can republish this to the GOC if necessary. I think this
advice was initially given to site admins when the Apel was first being
deployed (at a time when we weren't fully confident the Apel was bug
free and so having a backup copy of log files was seen as useful thing
to have).
> Is it only for backup purposes if the GOC fails and data is
> corrupted?
As mentioned above, data is stored within a local database at the site
so the Apel can resend its log data to the GOC (if any corruption
occurs). However, to recover from db corruption for a particular site,
the site admin should backup the local mysql db using the mysqldump
utility.
Dave may like to comment on this as well, but I think the FAQ should be
updated to avoid this confusion.
Rob
--
Antonis Zissimos, Phd Candidate
National Technical University of Athens (NTUA)
School of Electrical and Computer Engineering
Computing Systems Laboratory
e-mail: [log in to unmask]
web: http://www.cslab.ece.ntua.gr/~azisi
Tel: +30-2-10-7722402
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